Environment

Situation

ERROR:
ORA-15063: ASM discovered an insufficient number of disks for
diskgroup "XXXâ.

(where XXX
is the disk group number.)

An Oracle
server using 5 additional raw disk devices (/dev/raw) gets Image
Safe Data (ZISD) on Sector #06 written or modified to all devices
when the novell-zislinx process loads. Oracle recognizes these
disk changes and as a result will not mount the /dev/raw devices on
startup.

To check if
the imaging service has written to the raw devices run:dd if=/dev/raw/rawX skip=5 count=1 | stringsIf you see the string "ZISDâ, then Oracle will reject this
device.